While not wishing to be bound by any theory, it is believed that the peroxygen compound and chelate react synergistically to remove most foreign deposits. The peroxygen compound releases oxygen molecules which break down bonds in the foreign deposit. The chelate reacts with and ties up dissolved metals in the water which would otherwise react with and neutralize the oxygen. It is further believed that the metasilicate and builder peptize or emulsify (e.g. solubilize) proteins or fat. The metasilicate and builder together provide sufficient alkalinity to sopanify the high levels of fat in many foreign deposits.
The peroxygen compound preferably includes a perborate or a percarbonate and more preferably a percarbonate. The perborate or percarbonate can be complexed with a metal selected from the group including sodium, lithium, calcium, potassium, and boron. The cleaning composition preferably includes from about 10% to about 40% by weight, and more preferably from about 25% to about 40% by weight, of the peroxygen compound. The metasilicate is preferably an anhydrous metasilicate complexed with a metal selected from the group including sodium and potassium. The metasilicate can be replaced with a sesquisilicate. The cleaning composition preferably includes from about 10 to about 30% by weight of the metasilicate.
The chelate is preferably a derivative of a carboxylic or phosphonic acid. More preferably, the chelate is selected from the group consisting of EDTA, NTA, and other derivatives of a carboxylic acid or a derivative of a phosphonic acid, such as poly(alkylphosphonic acid), (e.g., sold under the trademark
ACUSOL 505ND) . The EDTA acid is preferably in the form of a salt, such as a sodium salt ("ETDA-Na4 ") or a potassium salt, as the salt is more water soluble than the acid. The cleaning composition preferably includes from about 3 to about 8% by weight of the chelate.
It is preferred that the peroxygen compound, metasilicate, and chelate are all salts having the same cation. More preferably, all of the salts in the cleaning composition have the same cation. The preferred cation is sodium or potassium.
The builder preferably includes at least a sulfate or a carbonate and more preferably a sodium carbonate, sodium sesquicarbonate, sodium sulfate, and sodium bicarbonate. The carbonate is preferably a hydrated carbonate such as trona. The cleaning composition preferably includes from about 16 to about 75% by weight of the builder.
The ratios of the various components are important parameters in many applications. Preferably, the ratio by weight of the peroxygen compound to the chelator ranges from about 7:1 to 3:1 and more preferably is about 5:1. The preferred ratio by weight of the surfactant to the metasilicate preferably ranges from about 10 to 1 and preferably is about 5:1.
The cleaning composition can further include a surfactant, such as a wetting agent, emulsifying agent, or dispersing agent. The surfactant must be functional in an alkaline solution. Suitable surfactants are nonionic, anionic and amphoteric surfactants. Preferred nonionic surfactants include octylphenoxy-polyethoxy-ethanol (e.g., sold under the trademark TRITON X-100), nonyl phenoxy ethyleneoxy ethanol (e.g., sold under the trademark IGEPAL CO730), pol,234yoxy ethoxylated ethanol (e.g., sold under the trademark RENEX ZO), glycol fatty esters (e.g., sold under the trademark HALLCO-376-N), fatty acid alkylanolamid (e.g., sold under the trademark ALKAMIDE 2110), cetyldimethyl amine oxide (e.g., sold under the trademark AMMONYX CO), aliphatic polyether (e.g., sold under the trademark ANTAROX LF-344), polyethylenated alkyl glycol amide (e.g., sold under the trademark ANTAROX G-200), fatty alcohol polyether (e.g., sold under the trademark AROSURE 63-PE-16), polyoxyethylene sorbitol esters of mixed fatty and resin acids (e.g., sold under the trademark ATLAS G-1234), modified oxyethylated straight-chain alcohol (e.g., sold under the trademark RENEX 648), modified oxyethoxylated straight-chain alcohols (e.g. sold under the trademark PLURAFACRA,ZO), alkylaryl polyether (e.g., sold under the trademark TRITON CF10), trifunctional polyoxyalkylene glycols (e.g., sold under the trademark PLURADOT HA-410), diethylene glycol dioleate, polyethylene glycol recinaleate, polyethylene glycol dioleate, tridecyl alcohol, nonylphenol, and ethylene oxide condensation products that are based on propylene oxide-propylene glycol (e.g., sold under the trademark PLURONIC L-61). Preferred anionic, surfactants include ethoxylated (3 moles) phosphate ester (e.g., sold under the trademark TRITON QS-44), sodium sulfate of 2 ethyl-a-hexanol (e.g., sold under the trademark TERGITOL 08), sodium petroleum sulfonate (e.g., sold under the trademark PETRONATE K), sodium alkyl naphthahalene sulfonate (e.g., sold under the trademark PETRO AR, SELLOGEN K, NEKAL BX-78, ALKANOL B), dioctyl ester of sodium sulfosuccinic acid (e.g., sold under the trademark ABRESOL OT), sodium alkylaryl sulfonate (e.g., sold under the trademark AHCOWETANS), sodium salt of sulfated alkylphenoxy poly(ethyleneoxy) ethanol (e.g., sold under the trademark ALIPAL EO-526), sodium methyl n-oleyl-taurate (e.g., sold under the trademark AMATER G T), alkyl polyphosphate (e.g., sold under the trademark ATCOWET C2), sodium lauryl sulfate (e.g., sold under the trademark AVIROL 101), sodium N-methyl-N-tall oil acid taurate (e.g., sold under the trademark IGEPON TK-32), lauric alkyloamine condensate (e.g., sold under the trademark NOPCOGEN 14-L), fatty alcohol sulfate modified (e.g. sold under the trademark RICHOLOL 4940) and modified diethanolamides of fatty acids (e.g., sold under the trademark SHERCOMID). Preferred amphoteric surfactants include disodium N-tallow betamino dipropionate (e.g., sold under the trademark DERIPHATE 154), sodium derivative of dicarboxylic caprylic acid (e.g., sold under the trademark MIRANOL J2M, letithin (e.g., sold under the trademark CENTROL CA, LA), lauryl ampholytic (syndet) (e.g., sold under the trademark SCHERCOTERIC BASE 156), carboxylic acid derivatives of substituted imidazolines (e.g., sold under the trademark MONATERIC), complex coco betaine (e.g., sold under the trademark CARSONAM 3 AND 3147), fatty sulfobetaine (e.g., sold under the trademark LONZAINE CS), dicarboxylic coconut derivative triethanolamine (e.g., sold under the trademark MIRANOL TEA), dicarboxylic octoic derivative sodium salt (e.g. sold under the trademark MIRANOL JEM), dicarboxylic myristic derivative diethanolamine (e.g., sold under the trademark MIRANOL M2M-DEM), dicarboxylic myristic derivative monoethanolamine (e.g., sold under the trademark MIRANOL M2M-MEA), dicarboxylic myristic derivative sodium salt (e.g., sold under the trademark MIRANOL M2M-SF), dicarboxylic captic derivative diethanolamine (e.g., sold under the trademark MIRANOL S2M-DEA), and dicarboxylic capric derivative triethanolamine (e.g., sold under the trademark MIRANOL S2M-TEA). Preferably, the cleaning composition contains from about 0 to about 8% by weight, and more preferably from about 0.5 to about 6% by weight of the surfactant.
The cleaning composition can include a phosphate to help the chelate bind up free metals and keep soils in suspension. The preferred phosphate is sodium or potassium tripolyphosphate. The cleaning composition preferably includes from about 5 to about 25% by weight of the phosphate.
The cleaning composition can also include a gelling agent to provide a gel formulation for applying the cleaning composition to soiled objects. The cleaning ability of the cleaning composition is facilitated by the adherence properties of the gel. For instance, such gel formulations are particularly useful for thick charred organic buildups on barbecue grills. Preferred gelling agents include carboxymethyl cellulose, hydroxymethylcellulose and modified polyacrylamide. The preferred concentration of the gelling agent in the cleaning composition ranges from about 6 to 12% by weight.
